I have some NES ROMs
with Mario for this special SNES-tool. But I miss the backgroundsounds in the games. BS Super Mario Bros. 3
have different levels and maps between the original SMB3 in Super Mario Allstars.
Have you find a version of the BS Mario-games with sounds?
In BS SMB2 are not Background-music but strange gold-statues . he he.
is a hard game, but try make the player better. You must press "Tab" to make the intro faster in "ZSNES"-emulator.
That sounds interesting.
Where did you get those NES ROMs